Adding date to a vector of data

Question

Im having a little trouble with R and adding a date to a vector of data. I guess i\'m messing around with objects the wrong way?

Data: y (that is numeric[9])

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Answer 1

You don't have a data.frame, you have a vector. You can append data to a vector like so:

y <- rnorm(10)
names(y) <- letters[1:10]
cbind(Sys.Date(), y) # vector, see?

                  y
a 15883 -1.21566678
b 15883  0.98836517
c 15883 -1.01564976
d 15883 -0.59483533
e 15883 -0.40890915
f 15883  1.69711341
g 15883  0.05012548
h 15883  0.42253546
i 15883  1.05420278
j 15883  0.15760482

Adding data to vectors is through c.

c(Sys.Date(), y)

                        a            b            c            d            e            f            g            h            i 
"2013-06-27" "1969-12-30" "1970-01-01" "1969-12-30" "1969-12-31" "1969-12-31" "1970-01-02" "1970-01-01" "1970-01-01" "1970-01-02" 
           j 
"1970-01-01" 

To coerce to a data.frame and cbind the data, do this.

y <- data.frame(matrix(y, nrow = 1, dimnames = list(1, names(y))))
cbind(Sys.Date(), y)

  Sys.Date()         a          b         c        d         e         f        g        h         i         j
1 2013-06-27 0.3946908 0.09510043 0.9753345 -1.05999 -1.041331 0.5796274 0.125427 1.319828 -1.844391 0.3365856

Answer 2

Although the solution of @Roman Lustrik works, I think it is simpler:

> y$date <- Sys.Date()
> y
          a        b         c        d          e          f          g          h          i        j
1 -1.104803 1.184856 0.9791311 1.866442 -0.3385167 0.04975147 -0.1821668 -0.7745292 -0.9261035 1.021533
        date
1 2013-06-27